U.S. patent application number 11/311947 was filed with the patent office on 2006-05-11 for aggregate floor coating and method for applying same.
This patent application is currently assigned to TENNANT COMPANY. Invention is credited to Bruce F. Field, Robert J. JR. Tweedy.
Application Number | 20060099351 11/311947 |
Document ID | / |
Family ID | 26984429 |
Filed Date | 2006-05-11 |
United States Patent
Application |
20060099351 |
Kind Code |
A1 |
Field; Bruce F. ; et
al. |
May 11, 2006 |
Aggregate floor coating and method for applying same
Abstract
The invention is directed to an aggregate floor coating and
method/system for applying the same. In one embodiment, a base
layer of epoxy or equivalent material may be applied to a prepared
floor surface. Prior to curing of the base layer, a quantity of
aggregate flooring material, e.g., quartz particles, may be
broadcast over the exposed surface of the base layer. Upon curing
of the base layer, an ultraviolet (UV)-curable topcoat layer may be
applied. Exposure of the UV-curable topcoat layer to one or more
specific wavelengths of UV energy results in fast curing of the
topcoat layer, permitting quick resumption of floor traffic.
Coatings of the present invention provide numerous advantages, such
as allowing application of aggregate floor coatings in well-lit,
e.g., sun-exposed areas.
Inventors: |
Field; Bruce F.; (Golden
Valley, MN) ; Tweedy; Robert J. JR.; (Coon Rapids,
MN) |
Correspondence
Address: |
MUETING, RAASCH & GEBHARDT, P.A.
P.O. BOX 581415
MINNEAPOLIS
MN
55458
US
|
Assignee: |
TENNANT COMPANY
MINNEAPOLIS
MN
|
Family ID: |
26984429 |
Appl. No.: |
11/311947 |
Filed: |
December 20, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10324383 |
Dec 19, 2002 |
|
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11311947 |
Dec 20, 2005 |
|
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60345549 |
Jan 3, 2002 |
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Current U.S.
Class: |
427/487 ;
427/402 |
Current CPC
Class: |
Y10T 428/29 20150115;
Y10T 428/2982 20150115; E04F 21/24 20130101; Y10T 428/25 20150115;
F26B 3/28 20130101 |
Class at
Publication: |
427/487 ;
427/402 |
International
Class: |
B05D 1/36 20060101
B05D001/36 |
Claims
1. A method for applying a coating to a floor, the method
comprising: applying at least one curable base layer material and
particles of aggregate material to the floor; curing the at least
one curable base layer material to form an at least partially cured
base layer on the floor; applying an ultraviolet-curable topcoat
layer material over the at least partially cured base layer and the
particles of aggregate material; traversing the floor with a
movable source of ultraviolet energy; and curing the
ultraviolet-curable topcoat layer material, via exposure to the
movable source of ultraviolet energy, to form an ultraviolet-cured
topcoat layer.
2. The method of claim 1, wherein applying the at least one curable
base layer material and the particles of aggregate material to the
floor comprises: applying the at least one curable base layer
material to the floor; and distributing the particles of aggregate
material over the at least one curable base layer material.
3. The method of claim 1, wherein applying the at least one curable
base layer material and the particles of aggregate material to the
floor comprises: mixing the at least one curable base layer
material with the particles of aggregate material to form a base
layer slurry; and applying the base layer slurry to the floor.
4. The method of claim 1, wherein applying the at least one curable
base layer material and particles of aggregate material comprises
at least partially embedding the particles of aggregate material in
the at least one curable base layer material.
5. The method of claim 1, further comprising removing excess
particles of aggregate material prior to applying the
ultraviolet-curable topcoat layer material.
6. The method of claim 1, wherein the particles of aggregate
material comprise quartz granules.
7. The method of claim 1, wherein the particles of aggregate
material comprise paint flecks.
8. The method of claim 1, wherein the at least one curable base
layer material is curable by exposure to one or more of ambient
temperature, humidity, and visible light.
9. A method for applying a coating to a floor, the method
comprising: applying a curable base layer material to the floor;
distributing an aggregate material over an upper surface of the
curable base layer material; applying an ultraviolet-curable
topcoat layer material over the aggregate material and the curable
base layer material; traversing the floor with a movable source of
ultraviolet energy; and curing the ultraviolet-curable topcoat
layer material by exposure to the movable source of ultraviolet
energy to form an ultraviolet-cured topcoat layer.
10. The method of claim 9, further comprising at least partially
curing the curable base layer material before applying the
ultraviolet-curable topcoat layer material.
11. The method of claim 10, wherein distributing the aggregate
material occurs before complete curing of the curable base layer
material.
12. The method of claim 9, further comprising removing excess
aggregate material prior to applying the ultraviolet-curable
topcoat layer material.
13. The method of claim 9, further comprising: applying a second
curable base layer material over the aggregate material; and
distributing a second aggregate material over an upper surface of
the second curable base layer material.
14. The method of claim 9, further comprising: applying a second
ultraviolet-curable topcoat layer material over the
ultraviolet-cured topcoat layer; and curing the second
ultraviolet-curable topcoat layer material.
15. The method of claim 9, wherein distributing the aggregate
material comprises distributing a granular quartz material to
substantially cover the upper surface of the curable base layer
material.
16. The method of claim 9, further comprising preparing the floor
prior to applying the curable base layer material.
17. A method for applying a coating to a floor, the method
comprising: mixing a curable base layer material with an aggregate
flooring material to form a slurry; applying the slurry to the
floor; applying an ultraviolet-curable topcoat layer material over
the slurry; and curing the ultraviolet-curable topcoat layer
material by application of ultraviolet energy emitted from an
ultraviolet energy source passing over the floor.
18. The method of claim 17, further comprising at least partially
curing the slurry before applying the ultraviolet-curable topcoat
layer material.
19. The method of claim 17, wherein the aggregate flooring material
comprises a granular quartz material.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/345,549, filed 3 Jan. 2002, which is hereby
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to floor coatings
and, more specifically, to aggregate floor coatings, such as those
that may provide decorative and/or no-slip surfaces, and methods
for applying the same to a floor surface.
BACKGROUND
[0003] Aggregate floor coatings are generally known in the art.
Generally speaking, these coatings include one or more particles,
e.g., grits, embedded or otherwise contained within one or more
layers of the floor coating. Aggregate floor coatings are typically
used to provide a decorative and/or slip-resistant floor
surface.
[0004] To apply the aggregate floor coating to the floor surface,
the floor surface is typically prepared (e.g., repaired, cleaned,
etched) and a base layer, e.g., an epoxy material, is applied
thereto. The base layer is applied as a liquid coating that may be
subsequently cured to form a hardened layer. Particles of the
desired aggregate material, e.g., quartz granules, are broadcast
over the at least partially uncured base layer. After curing of the
base layer, a topcoat layer, which is also typically applied as a
curable liquid, may be applied over the particles of aggregate
material to seal the underlying base layer and to provide a
durable, stain-resistant layer over the entire floor surface. Once
the topcoat layer is completely cured, normal floor traffic may
resume. Curing of both the base layer and the topcoat layer is
generally achieved through thermal treatment and/or exposure to
ambient conditions.
[0005] Aggregate floor coatings provide numerous advantages. For
example, these coatings may protect the underlying floor surface
from damage associated with dirt, wear, exposure, or spillage. With
the use of decorative particles of aggregate material, e.g.,
colored or prismatic quartz particles, these coatings may also
provide a more aesthetically pleasing floor appearance and improve
overall ambient lighting (e.g., from increased floor reflection).
Moreover, aggregate floor coatings, with their textured appearance,
may hide floor surface imperfections, e.g., floor peaks and
valleys, more effectively than smooth finished coatings. The
three-dimensional shape of the particles of aggregate material also
provide a roughened floor surface that, for example, improves
traction. Still further, aggregate floor coatings may simplify
floor cleaning procedures.
[0006] However, even with these advantages, drawbacks exist. For
instance, cure times for many of the materials, e.g., the topcoat,
can be substantial, e.g., anywhere from several hours to days. As a
result, floor traffic may be significantly interrupted during the
floor coating process. While such interruptions may be acceptable
in limited circumstances, long cure times may make some application
of these coatings difficult, or, in some instances,
impractical.
[0007] Another problem with existing aggregate floor coatings is
subsequent discoloration, e.g., yellowing, of the underlying epoxy
base layer due to excessive light exposure. As a result, use of
aggregate floor coatings in heavily lit, e.g., sun-exposed, areas
is typically avoided.
[0008] Still another problem with current aggregate floor coatings
involves repair of damaged areas of the topcoat layer. More
specifically, due to the high cure times associated with current
topcoat materials, any damaged area is typically isolated after
topcoat repair to allow adequate time to cure. As a result,
repairing damage to even a small area of the topcoat layer may
necessitate a significant interruption (e.g., several hours to
days) of floor traffic in the immediate vicinity of the repair.
SUMMARY
[0009] The present invention provides an aggregate floor coating
and a floor coating method. Coatings and methods in accordance with
the present invention may offer substantially reduced cure times,
permitting rapid resumption of normal floor traffic. Moreover,
coatings and methods in accordance with the present invention may
provide a topcoat layer that provides ultraviolet protection to the
underlying base layer and aggregate material, thereby reducing
yellowing of the same. Coatings and methods of the present
invention may also simplify repair of the topcoat layer by
permitting rapid curing of the same.
[0010] In one embodiment, a floor coating is provided. The floor
coating includes a cured base layer formed from a curable base
layer material, and an aggregate flooring material associated with
the cured base layer. An ultraviolet-cured topcoat layer is also
included over the cured base layer and the aggregate flooring
material.
[0011] In another embodiment, a method for applying a coating to a
floor surface is provided, wherein the method includes applying at
least one curable base layer material and particles of aggregate
material to the floor surface, and curing the at least one curable
base layer material to form an at least partially cured base layer.
An ultraviolet-curable topcoat layer material is applied over the
at least partially cured base layer and the particles of aggregate
material; and the ultraviolet-curable topcoat layer material is
cured, via exposure to ultraviolet energy, to form an
ultraviolet-cured topcoat layer.
[0012] In yet another embodiment, a method for applying a coating
to a floor surface is provided. The method includes applying a
first curable base layer material to the floor surface, and
distributing a first aggregate material over an upper surface of
the first curable base layer material. A first ultraviolet-curable
topcoat layer material may be applied over the first aggregate
material and the first curable base layer material, and the first
ultraviolet-curable topcoat layer material may be cured by exposure
to ultraviolet energy to form a first ultraviolet-cured topcoat
layer.
[0013] In still yet another embodiment, a method for applying a
coating to a floor surface is provided in which the method includes
mixing a curable base layer material with an aggregate flooring
material to form a slurry. The slurry is then applied to the floor
surface and an ultraviolet-curable topcoat layer material is
applied over the slurry. The ultraviolet-curable topcoat layer
material may be cured by application of ultraviolet energy from an
ultraviolet energy source.
[0014] The above summary of the invention is not intended to
describe each embodiment or every implementation of the present
invention. Rather, a more complete understanding of the invention
will become apparent and appreciated by reference to the following
detailed description and claims in view of the accompanying
drawing.
BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING
[0015] The present invention will be further described with
reference to the views of the drawing, wherein:
[0016] FIG. 1 is a diagrammatic, cross-section view of an aggregate
coating, such as an aggregate floor coating, in accordance with one
embodiment of the present invention (layer thicknesses are
exaggerated for illustration purposes);
[0017] FIG. 2 is a perspective view of an exemplary curing
apparatus;
[0018] FIG. 3 is a block diagram illustrating an exemplary method
of applying an aggregate floor coating of the present invention to
a floor surface; and
[0019] FIG. 4 is a block diagram representing another exemplary
method of applying an aggregate floor coating of the present
invention to a floor surface.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] In the following detailed description of exemplary
embodiments, reference is made to the accompanying figures of the
drawing which form a part hereof, and in which are shown by way of
illustration specific embodiments in which the invention may be
practiced. It is to be understood that other embodiments may be
utilized and structural changes may be made without departing from
the scope of the invention.
[0021] The instant invention is generally directed to aggregate
floor coatings and methods for applying the same to a floor
surface. The aggregate floor coating ideally includes an aggregate
flooring material therein. As used herein, "aggregate flooring
material" may include most any material, but generally includes
materials that provide either or both a particular utility (e.g.,
no-slip surface) or decorative appearance (e.g., three-dimensional
texture or color variation) to the floor surface. To achieve this
result, the aggregate flooring material may include particles that
provide the floor coating with a three-dimensional texture.
[0022] Most any floor surface may benefit from the coatings and
methods of the present invention including, for example, concrete,
ceramic tile, wood, and vinyl. Moreover, while described herein
with reference to floor coatings, those of skill in the art will
realize that coatings and methods in accordance with the present
invention may be used to coat non-floor surfaces as well. In fact,
this invention may find application with most any substrate
surface.
[0023] Broadly speaking, coatings and methods of the present
invention provide an aggregate floor coating having a curable base
layer (also referred to herein as "base coating") covered with an
aggregate flooring material. After curing of the base layer, an
ultraviolet (UV)curable topcoat layer (also referred to herein as
"topcoating"), is then applied over the combined base layer and
aggregate flooring material. Subsequent UV illumination of the
topcoat layer results in relatively instant curing of the same.
Instant curing permits, among other advantages, a substantial
reduction in floor traffic interruption. Other advantages of the
present invention are described in more detail below.
[0024] The term "curable" is used herein to refer to reactive
systems that irreversibly solidify upon the application of heat
and/or other sources of energy, such as E-beam, ultraviolet,
visible, etc., or with time upon the addition of a chemical
catalyst, moisture, and the like. The irreversible solidification
may involve polymerization, crosslinking, or both.
[0025] The term "instant curing" is defined herein to include
substantial curing of the coating material relatively instantly,
e.g., within several seconds or less. "Substantial curing" or
"substantially cured" includes most any degree of curing or
hardening of the identified coating layer material that results in
at least a tack-free (e.g., not wet) coating surface.
[0026] For simplicity, embodiments of the present invention are
described herein as utilizing quartz granules as the aggregate
flooring material. However, other naturally and artificially
colored silicas, grits (e.g., sand, silicon carbide, crystallized
aluminum oxide), flake materials (e.g., paint flecks or chips or
the like), or most any other suitable particulate material (e.g.,
rubber or plastic fragments) may also be utilized as the aggregate
flooring material without departing from the scope of the
invention.
[0027] An exemplary floor coating 15 in accordance with the present
invention is illustrated in cross section in FIG. 1. Here, a
curable, first base layer 20 lies over a substrate surface (e.g., a
concrete floor surface 10). The base layer 20 is, in one
embodiment, a cured epoxy resin material such as the two-part
ECO-MPE/ECO-FSE, (part A)/ECO-MPE/ECO-PT (part B) epoxy resin floor
coating product sold by the Tennant Company of Minneapolis, Minn.,
USA. However, as those of skill in the art will recognize, other
curable base layer materials may be used to form the base layer
20.
[0028] Where it is helpful to describe the invention, the term
"base layer material" is used to identify the base layer 20 in its
uncured, liquid form, e.g., as it exists prior to and/or during
application to the floor surface 10, while the term "base layer" is
used to identify the resulting layer 20 after deposition, e.g., the
base layer material after it has been partially or fully cured to
form the layer structure. No other distinction is intended by the
use of these separate terms and thus both "base layer" and "base
layer material" are associated hereby with reference numeral 20 of
FIG. 1.
[0029] The base layer material 20 may be curable by exposure to one
or more of heat or other energy, e.g., ambient temperature,
humidity, and/or visible light.
[0030] A layer 30 of aggregate flooring material, e.g., quartz
granules 35 such as ECO-DQF (part C) sold by Tennant Co., may at
least partially cover the upper surface of the base layer 20. As
further explained below, the layer 30 is, in one embodiment,
applied prior to complete curing of the base layer 20. As a result,
at least some of the granules 35 may at least partially embed into
the base layer 20 or otherwise become substantially secured in
place upon subsequent curing of the base layer.
[0031] After curing of the base layer 20 (with the granules 35
thereon), one or more additional base layers and corresponding
layers 30 may be applied (not shown) to increase total floor
coating thickness.
[0032] A UV-curable topcoat layer 40, such as ECO-DQF/UV sold by
Tennant Co., may then be deposited over the aggregate flooring
material layer 30. The topcoat layer material preferably includes,
as further described below, photoinitiators that are reactive to
one or more particular, predetermined UV wavelengths. As a result,
application of UV energy at these particular wavelengths from a UV
source 50, may result in relatively instant curing of the topcoat
layer material.
[0033] Where it is helpful to describe the invention, the term
"topcoat layer material" may sometimes be used to identify the
topcoat layer in its uncured, liquid form, e.g., as it exists prior
to and/or during application, while the term "topcoat layer" is
used to identify the resulting layer 40 after deposition, e.g., the
topcoat layer material after it has been partially or fully cured
to form the layer structure. No other distinction is intended by
the use of these separate terms and thus both "topcoat layer" and
"topcoat layer material" are hereby associated with reference
numeral 40 of FIG. 1.
[0034] An exemplary UV curing apparatus 55 having UV source 50
attached thereto is illustrated in FIG. 2. For a discussion of
other exemplary apparatus that may be used to cure the topcoat
layer 40, see, e.g., U.S. Pat. No. 6,096,383 to Berg et al., or
copending application Ser. No. 10/086,790, entitled "Methods and
Apparatus for Curing Floor Coatings Using Ultraviolet Radiation."
Other UV curing devices, including other push-powered or
self-propelled, walk-behind or riding devices, as well as handheld
devices, may also be used.
[0035] While a preferred topcoat layer 40 is described herein as
ECO-DQF/UV, other UV-curable layer materials (and correspondingly,
other UV curing apparatus) may certainly be used without departing
from the scope of the invention. In fact, the topcoat layer 40 of
the present invention may include, for example, most any UV-curable
urethane-based copolymer. For instance, in another embodiment, the
topcoat layer 40 is produced by NorIand Products, Inc. of New
Brunswick, N.J. (USA), under the designation SW3. Another exemplary
topcoat layer material is made by Summers Optical of Fort
Washington, Pa. (USA), and sold under the designation VTC-2. Most
any other material or substance, e.g., acrylates, epoxy acrylates,
and urethane acrylates, that polymerizes under application of UV
radiation may be used as a topcoat layer material without departing
from the scope of the invention.
[0036] In addition to being UV-reactive, the material of the
topcoat layer 40 may include conventional curing agents which
permit curing by exposure to ambient light or sunlight. As a
result, floor areas missed or not completely cured by the UV curing
apparatus 55, e.g., corners and edges adjacent a wall or other
obstacle, may still cure completely over time.
[0037] Various additives may optionally be included in the material
of the topcoat layer 40. For example, in many applications,
protection against static electricity is desirable. In these
instances, electrically conductive additives, e.g., indium tin
oxide, nickel-coated graphite, silver-coated graphite, and/or
gold-coated graphite, may be added to the topcoat layer material.
These additives may be beneficial where they provide the topcoat
layer 40 with electrically conductive properties which eliminate,
or at least reduce, static electricity. These additives preferably
do not interfere with the curing process and typically will not
affect the color of the topcoat layer 40. Examples of some other
additives which may be included with the topcoat layer material
include colorants (powder or liquid form) and texturing
components.
[0038] To promote quick curing of the topcoat layer 40, topcoat
layer materials of the present invention include components that
are preferably reactive to, i.e., cured by, UV radiation of at
least two different wavelengths. For example, UV radiation at a
first wavelength of about 350 nanometers (nm) to about 380 nm and,
more preferably, at a wavelength of about 365 nm provides what is
known as deep curing. Deep curing cures that portion of the topcoat
layer 40 closest to the floor surface and furthermore promotes
adhesion of the topcoat layer with underlying layers, e.g., base
layer 20 and aggregate flooring material layer 30 of FIG. 1.
Subsequent to, or simultaneous with, the application of the first
wavelength, UV radiation at a second wavelength of about 240 nm to
about 270 nm and, more preferably, about 254 nm is applied. This
second wavelength of UV radiation provides surface curing and
assists in complete curing of the topcoat layer 40.
[0039] In one embodiment, the UV source 50 (see FIG. 1) may include
one or more UV lamps (not shown) located under a hood 51 (see FIG.
2). Such lamps may preferably be medium pressure mercury flood
lamps having either a ballast incorporated on the lamp itself
(self-ballasted), or an external ballast.
[0040] Ideally, each lamp is selected such that the dopants therein
provide energy "spikes" at the desired wavelengths, e.g., at the
specific wavelengths that activate the UV-reactive components in
the topcoat layer 40. Stated another way, the lamps are matched
with the topcoat layer material in that a significant portion of
the UV energy emitted by each lamp occurs at the desired
wavelengths, e.g., at 365 nm and 254 nm.
[0041] While the topcoat layer material is described as responsive
to specific UV wavelengths, other wavelengths are certainly
possible. In fact, topcoat layer materials responsive to most any
wavelengths are possible, provided that the UV-reactive components
within the topcoat layer material are selected to match the
particular wavelengths of UV radiation emitted by the UV radiation
source 50. By matching the topcoat layer material to the UV
radiation in this way, relatively instantly curing of the topcoat
layer 40 may occur with only minimal power input. Low power curing
offers numerous advantages including, for example, reduced heat
and, thus, less opportunity to overcure or "burn" the topcoat layer
40.
[0042] An exemplary UV source 50 operates with low power, e.g.,
effective power consumption of no more than about 75 watts per inch
of cured coating width. "Cured coating width" refers to the
transverse, e.g., side-to-side, "line" of effective cure width. For
example, effective power consumption by the UV source 50 may be
about 25 to about 75 watts per inch of cured coating width and,
more preferably, about 40 to about 60 watts per inch of cured
coating width.
[0043] In one embodiment, the UV source 50 includes three separate
lamps (not shown) under the hood 51 (FIG. 2) that effectively
illuminate a width of about 24 inches (in). The UV source 50 has a
total effective power input of about 1200 watts, or about 50 watts
per inch of cured coating width. The UV source 50 is preferably
positioned above the floor surface 10 (see FIG. 1) at a working
height that ensures sufficient UV radiation is delivered to the
floor (e.g., positioned about 4 in to about 7 in above the floor
surface). Experiments suggest that this configuration allows curing
of the topcoat layer 40, without burning, at travel speeds less
than 3 inches/second (in/s). In addition, this configuration may
result in substantial curing at speeds up to and beyond 8 in/s.
[0044] The resulting cured floor surface 45 (see FIG. 1) preferably
has a decorative, three-dimensional appearance due in part to the
granules of layer 30. The extent of this three-dimensional
appearance may be at least partially controlled by selection of the
aggregate size of the granules 35, as well as the characteristics
of the topcoat layer 40 (e.g., viscosity).
[0045] FIGS. 3 illustrates a method for applying a floor coating in
accordance with one embodiment of the present invention. An initial
step of cleaning and preparing the substrate surface, e.g., the
floor surface 10 of FIG. 1, is identified at reference numeral 100.
This preparation may be accomplished in accordance with procedures
known in the art. For example, detergent scrubs and chemical
etching may be utilized if dictated by floor condition.
[0046] Other preparations may vary depending on the floor type and
condition. For example, in some situations, a previously applied
floor coating must first be removed before an aggregate floor
coating in accordance with the present invention may be applied.
Removal may be accomplished in any number of ways. For instance,
the coating may be softened with a solvent stripper and manually
scraped off. More preferably, products such as those sold by
Tennant Company under the name ECO-PREP may be used (for example,
in conjunction with a sanding machine as described in U.S. Pat. No.
4,768,311 to Olson) to remove the old coating and prepare the floor
surface. Some floors may further require scrubbing, vacuuming,
and/or acid-etching to ensure the floor surface is clean and
capable of forming a strong adhesive bond with the new floor
coating.
[0047] After surface preparation, a base layer (e.g., base layer 20
of FIG. 1) may be applied over the substrate surface at 110. As
mentioned above, while most any curable material suitable for
forming the desired base layer is within the scope of the
invention, epoxy resin materials suitable for floor covering are
preferred.
[0048] The thickness of the base layer may be selected based upon
the particular application. Preferably, thicknesses from about
0.005 in to more than 0.02 in, and more preferably from about 0.01
in to about 0.02 in, provide sufficient substrate protection as
well as an acceptably thick base layer for the subsequently applied
aggregate particles (the granules 35 of FIG. 1). However, these
ranges are not limiting as other thicknesses are certainly
possible. For example, where the floor surface is uneven or has
some degree of surface variation, an initial "precoat" of epoxy
resin (or other material) may be applied to smooth the floor
surface prior to application of the base layer. When such a precoat
of epoxy resin is applied, the actual thickness of the base layer
may be effectively increased by the thickness of the precoat.
[0049] Application of the base layer material may be accomplished
in accordance with most any technique known in the art. For
example, the base layer material may be poured onto the floor and
distributed with a squeegee. For thicker base layers, a notched
squeegee may be used. A nap roller may be used to remove puddles
and lap marks left by the squeegee ("backrolling"). Use of spiked
epoxy shoes permits freedom of movement over the wet floor surface.
While dependent on the desired thickness of the base layer,
backrolling the base layer material such that it covers about 100
feet/gallon (ft.sup.2/gal) to about 150 ft.sup.2/gal is typical
when using the Tennant two-part ECO-MPE/ECO-FSE, (part
A)/ECO-MPE/ECO-PT (part B) epoxy resin floor coating mentioned
above.
[0050] After the base layer material 20 is applied, aggregate
flooring material particles, e.g., quartz granules 35 of FIG. 1,
may be distributed or broadcasted over an upper surface of the base
layer material at 120 (see FIG. 3). The granules 35 that make up
the aggregate flooring material are preferably distributed over
substantially all of the upper surface of the base layer 20 (i.e.,
little or no areas of the base layer 20 remain exposed after
application of the aggregate flooring material particles) while the
base layer is still at least partially uncured.
[0051] While not wishing to be limited to any particular granular
size, the quartz granules 35 of the Tennant ECO-DQF product may be
about 20 U.S. Mesh to about 100 U.S. Mesh (e.g., may have a
diameter, or equivalent external dimension, ranging from 0.03 in to
0.006 in) and, more preferably, about 30 U.S. Mesh to about 50 U.S.
Mesh (particle diameter of about 0.02 in to about 0.012 in).
[0052] To assist in the distribution of particles over the entire
surface of the base layer 20, a mechanical blower, e.g., an
apparatus similar to the common handheld leaf blower, may be used.
Aggregate coverage rates may vary as a function of several factors,
e.g., particle size, desired result, etc. However, coverage rates
of about 0.25 pounds/ft.sup.2 (lb/ft.sup.2) to about 0.5
lb/ft.sup.2 are common.
[0053] After broadcasting the aggregate flooring material at 120,
the base layer 20 is allowed to at least partially cure. Depending
on the chemistry of the base layer material and the ambient
conditions, curing may take anywhere from a few hours to 10 hours
or more.
[0054] After curing of the base layer 20, the loose aggregate
flooring material, e.g., quartz granules 35, may be removed from
the base layer at 130 (see FIG. 2) by sweeping, vacuuming, etc. If
desired, processes 110, 120, and 130 may optionally be repeated.
That is, a second base layer (not shown) may be applied over the
aggregate flooring material layer 30, and a second aggregate
flooring material layer broadcast over the second base layer using
the same or different coverage rates. Thus, greater floor coating
thicknesses may ultimately be obtained.
[0055] Once the base layer(s) has cured and excess aggregate
material removed from its surface, a UV-curable topcoat layer
material (e.g., topcoat layer material 40 of FIG. 1) may be applied
over the base layer(s) and aggregate material layer(s) at 140 with
a squeegee or by other methods. A backroller may be used to evenly
distribute the topcoat layer material. The thickness of the
UV-curable topcoat layer material may vary depending on the
application. While thicknesses of about 0.001 in to about 0.02 in
are possible, coverage rates of about 100 ft.sup.2/gal to about 150
ft.sup.2/gal are desirable when using the Tennant ECO-DQF quartz
granules described herein (e.g., resultant layer thickness of about
0.010 in to about 0.016 in). However, coverage rates up to about
550 ft.sup.2/gal are contemplated.
[0056] The time delay in application of the UV-curable topcoat
layer 40 may be adjusted to ensure adequate bonding of the
UV-curable topcoat layer 40 to the base layer/aggregate flooring
material layers.
[0057] After application of the topcoat layer material, it may be
cured by application of UV energy at 150 (see FIG. 3). The floor
coating is then generally immediately ready for traffic.
[0058] If less texture of the floor coating is desired, processes
140 and 150 may be repeated. That is, a second topcoat layer (not
shown) may be applied over the first topcoat layer 40 and cured.
Such subsequent applications of the topcoat layer material may be
of the same or different coverage densities, e.g., about 100
ft.sup.2/gal to about 200 ft.sup.2/gal. Unless second applications
of the topcoat layer material are repeated soon after curing of the
first UV-curable topcoat layer though, e.g., within about 4 hours,
additional surface preparation of the first topcoat layer (e.g.,
sanding) may be required.
[0059] Floor coatings and methods in accordance with the present
invention may provide numerous benefits over other floor coatings
known in the art. For example, by using a cured base layer or
underlay (e.g., base layer 20 of FIG. 1) with a UV-curable topcoat
layer (e.g., topcoat layer 40 of FIG. 1), a relatively thick floor
coating may be obtained. Moreover, the UV-curable topcoat layer 40
of the present invention may be relatively quick-curing, permitting
resumption of normal floor traffic more quickly than with other
aggregate floor systems.
[0060] Floor coatings applied in accordance with the present
invention may significantly reduce coating discoloration, e.g.,
yellowing, a problem common with many other epoxy resin base
layers. This resistance to discoloration may be attributable to
many factors. For instance, the UV-curable topcoat layer itself is
UV-stable after curing and may provide a filtering effect. Further,
discoloration of the epoxy resin base layer may be substantially
reduced due to factors such as the blocking effect of the aggregate
flooring material. That is, when the base layer is substantially or
completely covered by quartz particles, little light may actually
reach the base layer. To further improve the ability of the coating
to resist discloration, non-yellowing aggregates may be used. Due
to its ability to resist discoloration, aggregate floor coatings in
accordance with the present invention may be used in sun-exposed
areas.
[0061] Another potential advantage of the present floor coatings is
the low energy required for UV curing. That is, when UV topcoat
layers that are curable with the dual wavelength curing methods
described herein are used, little curing energy may be required
and, thus, little shrinkage of the coating may occur. Therefore,
aggregate floor coatings as described herein may be particularly
advantageous for coating surfaces that are adverse to shrinkage,
e.g., vinyl. Moreover, low power requirements permit curing of
aggregate floor coatings in accordance with the present invention
using a curing apparatus that is powered by conventional low-power
sources, e.g., a 120V AC, 15 amp outlet or a small generator.
[0062] Yet another potential advantage of the present invention is
that scratches in the topcoat layer may be easily and quickly
repaired. For example, a scratch may be repaired by simply sanding
the scratch, reapplying the UV-curable topcoat layer material to a
localized area, and UV-curing the localized area.
[0063] Other embodiments of the invention are also possible. For
example, FIG. 4 illustrates an embodiment wherein the base layer
material and the aggregate flooring material are mixed to form a
base layer slurry prior to application. In this embodiment, the
floor is cleaned/prepared at 210 in a known manner. The base layer
material is then mixed with the aggregate flooring material, e.g.,
the base layer material 20 is mixed with the quartz granules 35, to
form a slurry at 220. The slurry is then applied to the substrate
or floor surface at 230 in a known manner, e.g., rolling, and
allowed to cure. The UV-curable topcoat layer material 40, as
already described herein, is applied at 240 after the base layer
has at least partially cured and, more preferably, fully cured. The
UV topcoat layer may then be cured at 250 by application of UV
energy as already described herein.
[0064] The complete disclosure of the patents, patent documents,
and publications cited in the Detailed Description of Exemplary
Embodiments and elsewhere herein are incorporated by reference in
their entirety as if each were individually incorporated.
[0065] Exemplary embodiments of the present invention are described
above. Those skilled in the art will recognize that many
embodiments are possible within the scope of the invention. For
instance, other base layers, aggregate flooring materials, and
UV-curable topcoats may be used. Other variations, modifications,
and combinations of the coatings and processes described and
illustrated herein can certainly be made and still fall within the
scope of the invention. Thus, the invention is limited only by the
following claims, and equivalents thereto.
* * * * *